Irrigation of agricultural land has long been considered by many an energy inefficient means of producing crops. However, recently academics have started to contest this preconception. Researchers at the University of Nebraska now believe that irrigated corn cultivated on dry plains might not be as energy-intensive, costly and risky as previously believed.

Agronomists Ken Cassman and Patricio Grassini say that irrigation techniques that produce huge crop yields can actually be carried in an efficient way, that also have a low impact on the surrounding environment. The academics added that their portfolio of research was based on field data collected over a period of several years from commercial production fields in Nebraska, in addition to U.S. Department of Agriculture (USDA) data and farmer surveys.

“We found that irrigated corn had substantially larger net energy yield and less greenhouse gas emissions per unit of grain produced than corn from rainfed systems with much smaller input levels and lower yields” said Grassini. He argued that a crop’s energy efficiency should be measured on a yield basis, rather than on the land area used.

While the researchers accept that irrigation uses more resources – water in particular – than alternative techniques, they claim that in the long term its resource balance makes for a more balanced system than dryland production in states such as Nebraska. Grassini said that converting irrigated land to dryland yields decreased greenhouse gases per acre, but conversely requires double the acreage in production to produce the same amount of grain.

“Thus it is penny-wise and pound foolish to convert irrigated agriculture back to dryland production for the sake of reducing greenhouse gas emissions,” Grassini told Agriculture.com. The researchers said they made a concerted effort to take the issue of water scarcity in the U.S. midsection into account in their research. They said they tried to show how water availability can work alongside systems such as center-pivot irrigation to maximize crop yields.

“The story of irrigated corn in Nebraska can be taken as a benchmark for other current and future irrigated cropping systems because it shows that achieving high yields, high energy efficiency, and low global warming potential are not mutually exclusive goals in real-world commercial farming” precise Grassini. “The findings do not mean irrigated corn systems can’t be made more energy efficient. Continued progress can come with use of best management practices, including rotation of corn with soybeans rather than continuous corn, replacement of surface irrigation with pivot irrigation systems, use of conservation tillage practices rather than conventional disc-plowing, and fine-tuning applications of nitrogen fertilizer and irrigation water” added Cassman.